CAJ | 학술논문

利用河海大学TSW-40型真三轴仪,对粗粒土进行π平面上的等p(球应力)、等b(中主应力系数)试验,研究粗粒土在π平面上破坏应力比Mb与b的关系。试验结果表明：Mb 随着b的增大而减小；b值较小时其变化对Mb 的影响较大,b值较大时其变化对Mb 的影响则较小；在相同b值下,Mb随着p的增大而减小,强度表现出非线性特性。将等σ3面上的破坏准则、Mohr-Coulomb破坏准则、粗粒土的应力不变量破坏准则、Lade-Duncan破坏准则、Matsuoka-Nakai破坏准则这5种破坏准则在π平面上的破坏线与试验结果比较,验证其对粗粒土的适用性。结果显示,粗粒土等σ3面上的破坏准则由于考虑了中主应力的影响,比Mohr-Coulomb破坏准则更符合试验结果,且可以较方便地考虑粗粒土的强度非线性；粗粒土的应力不变量破坏准则介于Lade-Duncan破坏准则和Matsuoka-Nakai破坏准则之间,与试验结果较接近。
이용하해대학TSW-40형진삼축의,대조립토진행π평면상적등p(구응력)、등b(중주응력계수)시험,연구조립토재π평면상파배응력비Mb여b적관계。시험결과표명：Mb 수착b적증대이감소；b치교소시기변화대Mb 적영향교대,b치교대시기변화대Mb 적영향칙교소；재상동b치하,Mb수착p적증대이감소,강도표현출비선성특성。장등σ3면상적파배준칙、Mohr-Coulomb파배준칙、조립토적응력불변량파배준칙、Lade-Duncan파배준칙、Matsuoka-Nakai파배준칙저5충파배준칙재π평면상적파배선여시험결과비교,험증기대조립토적괄용성。결과현시,조립토등σ3면상적파배준칙유우고필료중주응력적영향,비Mohr-Coulomb파배준칙경부합시험결과,차가이교방편지고필조립토적강도비선성；조립토적응력불변량파배준칙개우Lade-Duncan파배준칙화Matsuoka-Nakai파배준칙지간,여시험결과교접근。
Several experiments in which both p ( spherical stress) and b ( the coefficient of intermediate principal stress) remained constant on the π-plane were performed on coarse-grained soil by the TSW-40 type true triaxial apparatus at Hohai University. The relationship between the peak value of stress ratio Mb and the value of b in these tests was studied. The test results indicate that Mb decreases with the increase of b, and the influence of b on Mb is greater when b is small, while the influence is small when b is large. The test results also show that Mb decreases with the increase of p under the same value of b, which shows that the strength of coarse-grained soil has nonlinear properties. The failure lines on the π-plane based on five failure criteria, including the failure criterion on a σ3 - constant plane, the Mohr-Coulomb criterion, the stress-invariant failure criterion, the Lade-Duncan criterion, and the Matsuoka-Nakai criterion, were drawn and compared with the test results in order to verify the applicability of these criteria to coarse-grained soil. It is shown that the results of the failure criterion on a σ3 -constant plane of coarsegrained soil are closer to the test results than those of the MohrCoulomb criterion, owing to consideration of the influence of intermediate principal stress, and it is convenient to take strength nonlinearity into account. It is also shown that the results of the stressinvariant failure criterion of coarsegrained soil are between those of the LadeDuncan criterion and the MatsuokaNakai criterion, and they fit the test results better.